Percussion hammer



United States Patent [72} Inventor Henry G. Warrington Palm Beach, Fla.[2]] Appl. No. 774.082 [22] Filed Nov. 7, 1968 [45] Patented Dec. 15,1970 [73] Assignee Vulcan lron Works, Inc.

Chattanooga, Tenn. a corporation of Illinois I 54] PERCUSSION HAMMER 4Claims, 9 Drawing Figs.

[52] US. Cl 173/127; 92/85. 92/144: 173/133, 173/138: 175/6 {51 Int. ClE02d 7/02 [50] Field ol'Search 175/6; 173/134-138, 127, 128, 133;92/144, 85

{561 References Cited UNITED STATES PATENTS 1,019,386 3/1912 Warrington92/85X 1,257,762 2/1918 Sturtevant 173/127 2,403,582 7/1946 Caudill92/144X 2,904,964 9/1959 Kupka 175/6 Primary Examiner--Ernest R. PurserAttorney-Mason, Kolehmainen, Rathburn & Wyss into the cylinder to cyclethe ram through power and return strokes.

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rr 16 ll LL OUT F" Y J 43 OUT [/I II I II/ I HENRY G. WARRINGTON IPERCUSSION HAMMER The present invention relates to a percussion hammerand, more particularly, to a submersible pile driving hammer adapted fordriving piles under water.

Heretofore difficulty has been experienced in the operation of piledriving hammers under water. It has generally been necessary topressurize the interior of existing commercial pile driving hammers toprevent the ingress of water when the hammer is operated submerged.Moreover difficulty is encountered when steam is used as the workingfluid in a submersed hammer because of the cooling effect of the water.

One object of the present invention is the provision of a new andimproved percussion hammer.

Another object of the present invention is to provide a new and improvedsubmersible percussion hammer for driving piles and the like underwater.

Further objects and advantages of the present invention will becomeapparent as the following description proceeds and the features ofnovelty which characterize the invention will be pointed out withparticularity in the claims annexed to and forming a part of thisspecification.

In accordance with these and other objects of the present invention,there is provided an improved submersible percussion hammer of the typefor driving pile and the like under water. The submersible hammer isprovided with a differential diameter piston defining a ram andreciprocally positioned within a differential diameter cylinder. Ananvil is mounted in one end of the cylinder positioned in the path ofthe ram to receive percussion blows therefrom. The anvil is hermeticallysealed with the cylinder to prevent the ingress of water. Suitablecontrol means are provided for controlling the exhaust inlet of workingfluid into the cylinder tocycle the ram through power and returnstrokes.

Advantageously it is unnecessary to pressurize the interior of thepercussion hammer to prevent the ingress of water. Suitable internalrelief ports are provided adjacent the upper and lower ends of thecylinder to provide relief for fluid trapped above and below the ramduring the cycling thereof. Any small amount of water entering aroundthe anvil seal will readily be expelled by the working fluid in thepassageways of the hammer. Moreover advantageously voids in the cylindercasting created by the molding process may contain an endothermicchemical for the purpose of absorbing and retaining heat to keep thehammer body warm and resist the tendency of excessive cooling due to thelow temperature of sea water at great submergence depth.

For a better understanding of the present invention, reference may behad to the accompanying drawings wherein:

FIG. 1 is an elevational view of the improved percussion hammeraccording to the present invention;

FIG. 2 is a cross-sectional view of the percussion hammer of FIG. 1,shown with the ram at the top of its stroke;

FIG. 3 is a cross-sectional view of the percussion hammer of FIG. 1,taken at right angles to the view of FIG. 2, and shown with the ram atthe bottom of its stroke;

FIG. 4 is a cross-sectional plan view of the percussion hammer of FIG.I, taken along line 4-4 of FIG. 1;

FIG. 5 is a cross-sectional plan view of the percussion hammer of FIG.1, taken along line 5-5 of FIG. I;

FIG. 6 is a cross-sectional plan view of the percussion hammer ofFIG. 1. taken along line 6-6 of FIG. 1;

FIG. 7 is a cross-sectional plan view of the percussion hammer of FIG.1, similar to FIG. 4, but drawn to a larger scale, with the valvemechanism in the exhaust position during a power stroke of the ram;

FIG. 8 is a detail view of the valve mechanism of FIG. 7, illustratingthe valve member during the raising stroke of the ram; and

FIG. 9 is an enlarged detail view of the valve mechanism of thepercussion hammer I0 corresponding to detail 8 of FIG. 2.

Referring now to the drawings, there is illustrated an improvedsubmersible percussion hammer 10 suitable for driving pile or likeapplications under water. The hammer 10 includes a housing 11 defining adifferential diameter cylinder I2, being closed at the top by a cylinderhead I3 forming a lifting bail 14. The lifting bail I4 is adapted to beslung from the cable of a crane or other mechanism'so as to position thepercussion hammer 10 onto the top of a pile to be driven.

Within the cylinder 12 is a differential diameter piston 15 defining aram. Conveniently the ram 15 may be a one piece forging completelycontained within the cylinder I2. In the illustrated hammer, the cycleof the hammer is single acting, that is the ram I5 is powered up, anddropped by gravity. The ram 15 is prevented from radial rotation by aguide pin 16 extending through the housing 11 and aligning within agroove in the cylinder wall. The ram I5 is positioned to impinge upon ananvil 17 in the lower end of the cylinder I2. The anvil I7 is mountedfor limited movement within a sleeve I8 at the lower end of the hammer10. The anvil 17 is sealed against the ingress of water by suitablestatic or dynamic sealing means, depending upon the submersion depthrequirements. In the illustrated embodiment suitable hermetic sealingmeans 19 are provided in the sleeve 18 to hermetically seal between theanvil l7 and the cylinder 12.

At the lower end of the hammer is provided a wear ring 22 to minimizewear between the bottom of the hammer and a driving cap (not shown)normally interposed between the hammer and the pile being driven. Thedriving cap is cabled to the hammer through a plurality of lugs 23,FIGS. I and 6.

Control of the piston 15 is by a valve gear mechanism 25 within a fluidchamber or steam chest 26, best shown in FIGS. 7, 8 and 9. The valvegear mechanism 25 includes a rotary valve element 27 controlled by asurface cam 28 defined as a groove in the longitudinal side surface ofthe piston 15, and receiving a valve actuator portion or cam follower 29on the end of a valve arm 30 extending out of the fluid chamber 26. Thesurface cam 28, upon vertical reciprocation of the piston 15, willreciprocate the valve arm 30 between the positions illustrated in FIGS.7 and 8.

To control the reciprocation of the piston 15 defining the ram, there isprovided a plurality of fluid passageways interconnecting the fluidchamber 26, valve element 27, and the cylinder 12. More specifically,there is provided a passageway 32 interconnecting the fluid chamber 26with the cylinder 12, opening by a plurality of passageway ports 33intermediate the large and small diameter portions of the piston I5 soas to be in communication with the underside of the larger diameterportion of the piston I5. An exhaust passageway 34, FIG. 7, extends fromthe fluid chamber 26 opening to an exhaust fitting 35 for communicationwith the atmosphere. An inlet fitting 36 provides for the connection ofthe fluid chamber 26 to the source of working fluid, such as steam. Thevalve element 27 rocks about its central axis from the positionillustrated in FIG. 7 wherein the cylinder 12 is exhausted to theatmosphere, to the position illustrated in FIG. 8, wherein the cylinder12 is connected to the source of pressurized fluid.

Thus it will be understood that when the ram 20 is at its bottomposition, as illustrated in FIG. 3, the valve element will be in theposition illustrated in FIG. 8 connecting the inlet fitting 36 and inletpassageway 37 to the port 33 through the passageway 32. The workingfluid w will be effective to act against the lower surface of theenlarged diameter portion of the cylinder IS. The working fluid will, ofcourse, act against an area equal to the difference in diameter betweenthe enlarged portion of the piston 15 and thesmaller diameter portion ofthe piston 15. This working fluid will be effective to raise the piston15 upwardly, from the position illustrated in FIG. 3 to the positionillustrated in FIG. 2. However as the piston 15 approaches the-top ofits stroke, the valve arm 30 will shift to the position illustrated inFIG. 7. Thus the cylinder 12' will be disconnected from the source ofpressurized fluid, and will be exhausted to the atmosphere through thepassageway 32, the exhaust passageway 34. and the exhaust fitting 35.The piston 15 defining the ram will now drop by gravity to provide animpact blow against the anvil l7.

It is necessary to provide suitable relief above and below the piston toprevent excessive air cushioning and vacuum creation during the cyclingof the piston 15. In the illustrated embodiment there is provided aplurality of exhaust ports 40, FIGS. 2 and 3, adjacent the upper end ofthe cylinder 12, but spaced slightly below the cylinder head 13. Thus asthe piston moves upwardly, closing the ports 40, there will be entrappeda quantity of air forming a dashpot above the piston and preventing thepiston 15 from striking the cylinder head 13. Moreover, in thesubmersible hammer, it is necessary that no air be trapped in advance ofthe descending piston 15 for this trapped air will retard the descent ofthe piston 15. Therefore there is provided suitable relief ports 41 intothe lower end of the cylinder 12. The exhaust ports 40 and relief ports41 are in communication through a communicating passageway 42, which, inturn, is in communication with the atmosphere through the exhaustpassageway 34 and exhaust fitting 35 by means of an additionalpassageway 43, FIG. 7.

In order to prevent excessive cooling of the submerged hammer due to thepossible low temperature of sea water at great submergence depth, aplurality of voids 50, 51 and 52,

formed in the housing 11 by the casting process, may contain anendothermic chemical which will absorb and retain heat to keep thehammer body warm and resist excessive cooling.

' ,From the above detailed description, the operation of the submersiblepercussion hammer is believed clear. However, briefly, it will beunderstood that the percussion hammer 10 is positioned on the top of apile to be driven. The working mechanism of the percussion hammer is allhermetically sealed so that the percussion hammer may be used below thesurface of water. The hammer is of the single acting type wherein thevalve gear mechanism is effective to first introduce working fluid belowthe larger diameter piston thereby to raise the ram defining piston.Subsequently the valve gear mechanism 25 is actuated to exhaust the airfrom below the large diameter portion of the piston 15. The ram definingpiston will now fall by gravity, striking the anvil. The anvil ishermetically sealed with reference to the cylinder. Any small amount ofwater which may enter around the anvil seal will be expelled by the airbelow the piston 15. Advantageously the submersible hammer does notrequire pres- .su'rization of its interior to prevent the ingress ofwater. Suitable relief ports are provided so that both ascent air anddescent air are forced from the cylinder during the cycling of thepiston. Voids in the cylinder casting may suitably contain endothermicchemical to absorb and retain heat and resist excessive cooling of thesubmerged hammer.

Although the present invention has been described by reference to only asingle embodiment thereof, it will be apparent that numerous othermodifications and embodiments will be devised by those skilled in theart which will fall within the true spirit and scope of the presentinvention.

1 claim:

1. A submersible percussion hammer comprising a housing having definedtherein-a differential diametercylinder, a differential diameter pistonincluding a large diameter portion defining a piston element and a smalldiameterportion defining a ram element reciprocally positioned in, saidcylinder, spaced apart piston ring means adjacent opposite ends of saidpiston element, a surface cam defined on said piston elementintermediate said piston ring means, an anvil mounted for limitedmovement at one end of said cylinder positioned in the path of said ramto receive percussion blows therefrom, means forming a hermetic sealbetween said anvil and said cylinder, means controlling the exhaust andinlet of working fluid into saidcylinder between the differentialdiameters of said piston to cycle said ram through power and returnstrokes, said means including a valve gear mechanism operated by a camfollower cooperating with said surface cam, and means providing relieffor air above and below said piston during the cycling thereof. 1

2. A submersible percussion hammer as set forth in claim 1 wherein saidrelief means includes a plurality of ports commumcatmg with saidcylinder near but spaced apart from the upper end of said cylinder toprovide for release of fluid trapped above said piston during the returnstroke thereof, and further providing for the entrapping of a smallquantity of air near the completion of the return stroke to providecushioning of the piston during the up strokethereof.

3. A submersible percussion hammer as set forth in claim 1 wherein saidrelief means includes exhaust ports communicating with said cylinderadjacent the lowerend of the stroke of said piston to provide for reliefof fluid trapped below said piston during the power stroke thereof.

4. A submersible percussion hammer comprising a housing having definedtherein a differential diameter cylinder, a differential diameter pistondefining a ram reciprocally positioned in said .cylinder, an anvilmounted for limited movement at one end of said cylinder positioned inthe path of said ram to receive percussion blows therefrom, meansforming a hermetic seal between said anvil and said cylinder, meanscontrolling the exhaust and inlet of working fluid into said cylinderbetween the differential diameters of said piston to cycle said ramthrough power and return strokes, means providing relief for air aboveand below said piston during the cycling thereof, said housing beingformed with voids and endothermic chemical in said voids for absorbingand retaining heat.

